There are many web handling applications where it is desirable to have the web material in a completely relaxed condition after handling. If the web material is taken up on a roll, such a relaxed state cannot be achieved. However, when the web material is festooned (laid down with a back and forth oscillating movement), it is completely relaxed and will not have uneven stretch when utilized.
One particularly useful application of festooned material is in the manufacture of garments, particularly in the use of binding cloth strips, which binding is used at the collar, cuff, or wristband portions of garments being constructed. Typically, tubular knit cloth from a dye batch is passed through a biased slitter to make a strip of web material having a width of about 1 and 1/2 inches. If this strip of binding material is taken up on a roll, when it is used by the garment maker and taken off of the roll, there will be uneven stretch which is undesirable for a number of processing and quality control reasons. Also, when a roll is utilized, it is necessary to re-thread the equipment after each roll is used, and the material at the end of the roll (each end) is lost.
According to the present invention, it is possible to "take-up" the narrow strips of cloth to be utilized for binding in the construction of garments--and, in fact, any relatively narrow web material--so that such disadvantages are avoided by festooning the web material when it is being taken up, rather than rolling it. This allows a whole batch of dyed cloth to be festooned, and run by the garment maker in one continuous supply. Since the festooned material is completely relaxed, there will be no uneven stretch, and since it is not rolled, no material is lost.
There have been devices for festooning binding cloth strips in the past. For example, the inventors have had in operation such festooning devices that were operated electrically, with a cam effecting the festooning action, and depositing the festooned material onto a stationary platform mounted below a spreader. However, such machines have had far less-than-optimum operation, often laying down material unevenly so that all of the desirable features associated with festooning were not necessarily accomplished and/or the cloth was difficult to handle.
According to the present invention, a method and apparatus has been devised for the festooning of web material which avoids the drawbacks mentioned above. The drawbacks are avoided by utilizing a completely pneumatic variable speed (automatically changing speed in response to web speed) drive for oscillating the spreader during festooning, and/or by slowly oscillating a platform for receiving a web material, just below the spreader, in a dimension generally perpendicular to the dimension of oscillation of the spreader during festooning. These features individually greatly improve the festooning action, and, when combined by the virtually ideal mechanism and method for laying down web material in a completely relaxed, a readily reusable, even configuration of the web.
According to one aspect of the present invention, a festooning machine for web material is provided. The machine comprises the following elements: A frame. Spreader means, mounted on the frame, for engaging the web to guide it during festooning. Means mounted on the frame for directing web material to be festooned to the spreader means; and a fully pneumatic drive means mounted between the frame and the spreader means for effecting movement of the spreader means with respect to the frame so that the web is festooned. The pneumatic drive means preferably comprises an automatic variable speed pneumatic drive, i.e., one that is automatically adjusted in response to the speed of movement of the web of material being festooned. Automatic variable speed pneumatic drives are not conventional, and the particular pneumatic drive according to the invention has been constructed by connecting of the exhaust ports on either side of the piston in a pneumatic cylinder to a special exhaust valve.
The exhaust valve according to the invention includes a valve body with a cylindrically shaped actuator reciprocal within a cylindrically shaped passageway in the valve body. A number of exhaust ports, each with an adjustable orifice (such as provided by adjustment of a needle valve element) operatively communicate with the passageway in the valve body. Reciprocation of the actuator progressively uncovers one or more of the exhaust passages thereby progressively increasing the speed with which the air can exhaust from the cylinder through the ports, and thereby controlling the speed of movement of the piston rod of the pneumatic cylinder. The valve actuator is connected to a rod which engages a loop of the web material, and the rod is moved up and down depending upon the speed of movement of the cloth web.
Preferably, the web engaging rod is disposed in association with a loop of web material between front and rear rollers which are mounted to the frame above the spreader for relative rotation with respect to the frame. These rollers are operatively connected to the pneumatic cylinder so that reciprocation of the piston rod effects unidirectional driving rotation of the rollers. The rollers are also interconnected so that the rear roller (the one furthest from the spreader) is driven at a speed slightly greater (e.g., about 20% greater) than the speed of the front roller. As the speed of the cloth increases or decreases, the tension in the web material between the front and rear rolls will vary, thereby changing the position of the cloth engaging rod, which in turn changes the position of the valve actuator, which in turn controls the rate at which air can be exhausted from the pneumatic cylinder (and, therefore, the speed of reciprocation of the piston rod).
According to another aspect of the present invention, a festooning machine is provided which comprises the following elements: A frame. Spreader means mounted on the frame for engaging the web to guide it during festooning. Means mounted on the web for directing web material to be festooned to the spreader means. Drive means mounted between the frame and spreader means for effecting movement of the spreader means in a first dimension, with respect to the frame, so that the web is festooned. Means for supporting a platform to receive festooned web material adjacent the bottom of the spreader means; and means for oscillating the platform supporting means in a dimension generally perpendicular to the dimension of movement of the spreader means during festooning. A wheeled support preferably comprises a container (e.g., platform) mounting structure, and it is reciprocated by a pneumatic cylinder. Preferably, the drive means--as described above--is completely pneumatic for the festooning action too, to provide optimum results.
The invention also relates to a method of festooning a narrow cloth web while placing it on a platform. The method comprises the steps of:
(a) causing the web to move back and forth in a festooning action in a first horizontal direction, and to be deposited on the platform; and
(b) oscillating the platform in a second horizontal dimension generally transverse to said first direction during the practice of (a). Step (b) is practiced so that the platform moves approximately a distance corresponding to the width of the narrow cloth web for each one-half of a festooning action.
It is a primary object of the present invention to effect efficient festooning of web material. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.